I have a C760 with an interesting problem that I have not heard of before. Right now I am running Qtopia 1.5.4.

If the device enters into suspend mode by either closing the clam shell or letting it time out you have to hit the power button twice to get it back on. Once it comes on the keyboard doesn't work any more and the screen will stay on even when the clam shell is closed. The only way to fix it is to reboot the device. Here is the interesting part, if you select Suspend from the pop up menu the device will resume just fine.

I have installed several different ROMs on this thing and the problem persists.